The article makes an attempt to define Y. Fed’kovych’s literary vocabulary, the peculiarities of its creation, and the role of the author’s initiative in it. For this purpose, the materials of such a vocabulary are analyzed, which - in the poems, prose, dramas, journalistic, and even folkloric works of the writer - are contained, first of all, in the genre definitions formulated by him. The "terminological" content of this source base is considered according to the chronology of the literary activity of Y. Fed'kovych is considered, especially in the period of its creation, also about the history of creative intentions of this outstanding author, and not only by genres, because it was the only process of individual creative self-expression. It is underlined that an unusual artist used different literary terms also because he had two of the lower primary school classes, he was mostly away from the enlightened environment, science and he also learned it thirstily and independently, from reading throughout his life, and he was prone to definitions. The peculiarities of the early Y. Fed’kovich’s use of original, often based on folk song, literary genre forms and, consequently, and terms associated with them («kolyada», «pisnya», «hutsulka», «okrushok», «pamennik» etc.), which until now had no analogues in the author’s works, were noticed. Gradually, under the impression of the reading, the paradigm of the used terms expanded, illustrating the peculiarities of the ideological and aesthetic development of the writer. Fed’kovych’s vocabulary as a playwright especially demonstrates it, becoming evidence of the writer’s active search in this favourite field. The originality, non-boringness of the author’s thinking, and even multiplicity in the interpretation of his unstable, non-normalized appropriate vocabulary was largely evident there. As a result, it is stated that Y. Fed’kovych developed his own original literary terminological system, which successfully and coherently incorporated unique ethnically colourful purely authorial concepts, specific West-Ukrainian examples, and borrowings from other languages. This was also an indicator of the writer’s high culture of creative work, evidence of his understanding of the specifics of expressing, preserving, and transmitting important information. The perspective of the topic, the importance of a more active involvement in the appropriate consideration epistolary heritage of Y. Fed’kovych too, and the effort of linguists, not to mention the need for a more active application of this material into the historical, literary, and theoretical literary discourse, is pointed out. Keywords: Y. Fed’kovych, literary terms, writer’s literary vocabulary, genre specificity of the work, folklore, author’s, bookish.